body {
  padding: 300px;
}
.cart {
  width: 150px;
  position: relative;
  &:hover > .list {
    display: block;
  }
  &:hover > .btn {
    border-bottom-color: transparent;
  }
  .btn {
    border: solid 1px #ddd;
    padding: 10px;
    box-sizing: border-box;
    font-size: 14px;
    background: #fff;
    position: relative;
    top: 1px;
    z-index: 1;
  }

  .list {
    padding: 10px;
    width: 300px;
    border: solid 1px #ddd;
    right: 0;
    position: absolute;
    background-color: #fff;
    display: none;
    margin-top: -1px;
  }
}
